What should I do about the discharge of prostatic fluid (wadi) after urination, which necessitates a long time for purification (istinja'), and what should I do if I am outside the home and the water is insufficient?

Wadi (pre-seminal fluid) is impure by consensus, and one must perform istinja’ (cleansing) from it. Even if this takes five minutes, as long as it does not reach the point of سلس (incontinence). Istinja’ is not conditioned upon using water; it is permissible to perform istijmar (cleansing with solid objects) using a tissue or similar item when water is unavailable.